Mucuna gigantea subsp. gigantea

Wiriadinata, H., Ohashi, H. & Adema, F., 2016, Notes on Malesian Fabaceae (Leguminosae-Papilionoideae) 16. The genus Mucuna, Blumea 61 (2), pp. 90-124 : 108

a. subsp. gigantea

Distribution — Africa, Seychelles, India, Burma, China, Japan, Indochina; throughout Malesia; Australia, Solomon Islands, Hawaii, Tahiti, Niue Island, Cook Island, Mariana Islands, New Hebrides, New Caledonia.

Habitat & Ecology — Beaches, sand dunes, coastal forest, primary and secondary forest, along rivers and roads. Soil: volcanic ash, sand, limestone. Altitude up to 700 m. Flowering and fruiting: throughout the year.

Note — Pods often have a stipe up to 10 mm long. BNBFD 7393 (Keith) probably belongs here. According to the label the flower colour is pink. Several times M. gigantea was split into subspecies. However, the authors who proposed these splits use different characters, making it difficult to compare these subspecies. Verdcourt (1979) uses fruit characters (size of fruits and number of seeds), while Ohashi & Tateishi (1976) and Tateishi & Ohashi (1981) use flower characters (size of standard in relation to size of wings, length of the claw of wing petals in relation to the whole length of wing petals). In the Flora Malesiana region the subspecies described by Verdcourt are found: subsp. gigantea and subsp. plurisema . According to Verdcourt the differences between these subspecies are: subsp. gigantea : Flowers small. Fruits 10–18 by 3.5– 6 cm with 1–4 seeds; subsp. plurisema : Flowers larger (up to 4 cm). Fruits 15.5 by 3.5– 4 cm with 5–6 seeds. However, the flower-size in subsp. gigantea varies from 27 mm to 53 mm, so flower-size is not a good character. Pods of subsp. gigantea measure 8–18 by 3–6.5 cm. In this character there is no difference at all; the size of the pods of subsp. plurisema falls right in the range of subsp. gigantea . In specimens of subsp. gigantea pods may be found with 4–5 seeds. In the ovary up to six ovules may be found, so 6 seeds may be expected. To conclude: the differences as given by Verdcourt are insufficient to support subspecies. According to Ohashi & Tateishi (1976) and Tateishi & Ohashi (1981) the Malesian material belongs to subsp. gigantea . The other subspecies, subsp. tashiroi (Hayata) H.Ohashi & Tateishi , is a Taiwanese endemic.